Recently, in semiconductor integrated circuit devices including semiconductor devices, printed circuit boards, etc., the use of the so-called graphene sheet material as an electronic member having the properties of conductor is being studied.
The graphene sheet material includes a thin film graphene of 1 to 10 horizontal layers of graphite (graphen sheets), and the general materials driven from such thin film graphene, such as the chemically modified thin film graphene, etc. The graphene sheet material is superior in chemical stability while having various attractive characteristics, such as peculiar physical and electric properties, etc. and is noted as a constituent material of semiconductor devices.
Specifically, applications of the graphene sheet material to the interconnections and via structural members of semiconductor devices, and parts of semiconductor elements, e.g., graphene channel transistors and a graphene interconnections of LSI, etc. are being studied.
Conventionally, in forming the graphene sheet material, the process of transferring graphene sheets from a graphite bulk with an adhesive member, such as adhesive tape or others, the vacuum film-forming process, such as CVD method or others, etc. have been used.
The following are examples of related: Japanese Laid-open Patent Publication No. 2007-098357; Y. B. Mang et al., Nature, Vol. 438, p. 201 (2005); K. S. Novoselov et al., Science, Vol. 306, p. 666 (2004); and A. C. Ferrari et al., Physical Review Letters, Vol. 97, p. 187401 (2006).
To apply the graphene sheet material to downsized devices, such as semiconductor elements, etc., it is necessary that the graphene sheet material including a required layer number of graphene sheets are formed. However, the above-described conventional method of forming graphene sheet material cannot control a layer number of the graphene sheets.